[NeedMoreTea]

It seems to have the key components. An ephemeral timeline and new posts page, user submitted stories and content, and the like/upvote.

It's not a social network though. There's no concept of friends. Twitter is part way between the two. It barely groks user relationships - you subscribe to someone to see their stuff in your feed and that's about as far as it goes.

[doute]

Yes, very much so and it is also apparent by the content. You also don't have to have formal network to have a social network. The significant part is whether something behaves differently in the context of the network. Which I think one could clearly say about hacker news.